Understanding Nominal and Actual Sizes for Air Filters
When shopping for air filters for your AC or furnace, you may notice two different sizes listed: nominal size and actual size. Understanding the difference between these measurements is crucial to ensure you buy the right filter for your HVAC system.
What is Nominal Size?
The nominal size is the rounded, commonly marketed measurement of an air filter. It’s used for simplicity and doesn’t represent the filter’s precise dimensions. For example, a filter labeled as 16x20x1 may not actually measure exactly 16 inches by 20 inches by 1 inch.
Think of it as the “name” of the filter, not the exact size.
What is Actual Size?
The actual size is the true measurement of the filter, typically a fraction smaller than the nominal size. For example, a filter labeled 16x20x1 might have actual dimensions of 15.75 x 19.75 x 0.75 inches.
This slight reduction ensures the filter fits comfortably in the HVAC system without being too snug or too loose.
Watch Our Video On How To Measure Air Filters:
Why the Difference Matters
Choosing the wrong size air filter can lead to issues such as:
- Reduced efficiency: Gaps between the filter and frame may allow unfiltered air to pass through.
- Increased wear and tear: A poorly fitting filter forces your system to work harder, potentially shortening its lifespan.
- Poor air quality: Incorrect filters may not capture dust, allergens, or pollutants effectively.
How to Measure Your Air Filter
- Remove the current filter: Look at its dimensions printed on the side.
- Measure it yourself: Use a tape measure to get the exact height, width, and thickness.
- Match nominal size: When shopping, match the nominal size, but confirm the actual size to ensure compatibility.
Pro Tips for Finding the Right Filter
- Always check your HVAC manual for recommended filter sizes.
- Measure your air filter by finding the exact size: Length, Width, & Depth
- Consider ordering custom-sized filters if your system has unique requirements.
Stay Clean with Nordic Pure Filters
At Nordic Pure, we simplify the process of finding the perfect filter. Our wide range of high-quality filters includes clear sizing information, so you never have to second-guess your purchase.
Shop now and enjoy better air quality with filters that fit perfectly every time!
